Add per-request AI logging, DB batch queue, WS entity updates, and UI polish

- log_thread.py: thread-safe ContextVar bridge so executor threads can log
  individual LLM calls and archive searches back to the event loop
- ai_log.py: init_thread_logging(), notify_entity_update(); WS now pushes
  entity_update messages when book data changes after any plugin or batch run
- batch.py: replace batch_pending.json with batch_queue SQLite table;
  run_batch_consumer() reads queue dynamically so new books can be added
  while batch is running; add_to_queue() deduplicates
- migrate.py: fix _migrate_v1 (clear-on-startup bug); add _migrate_v2 for
  batch_queue table
- _client.py / archive.py / identification.py: wrap each LLM API call and
  archive search with log_thread start/finish entries
- api.py: POST /api/batch returns {already_running, added}; notify_entity_update
  after identify pipeline
- models.default.yaml: strengthen ai_identify confidence-scoring instructions;
  warn against placeholder data
- detail-render.js: book log entries show clickable ID + spine thumbnail;
  book spine/title images open full-screen popup
- events.js: batch-start handles already_running+added; open-img-popup action
- init.js: entity_update WS handler; image popup close listeners
- overlays.css / index.html: full-screen image popup overlay
- eslint.config.js: add new globals; fix no-redeclare/no-unused-vars for
  multi-file global architecture; all lint errors resolved

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/plugins/ai_compat/text_recognizer.py

@@ -51,6 +51,10 @@ class TextRecognizerPlugin:
             other=str(raw.get("other") or ""),
         )
 
+    @property
+    def model(self) -> str:
+        return self._client.cfg["model"]
+
     @property
     def max_image_px(self) -> int:
         return self._client.cfg["max_image_px"]